It suddenly occurred to him he had left his keys in the office.(·江西)A. whetherB. whe

问题补充：

It suddenly occurred to him he had left his keys in the office.(·江西)

A. whether

B. where

C. which

D. that

答案：

A. whether

B. where

C. which

(答案→)D. that

解析：句意：他突然想起他把钥匙落在办公室里了。It occurred to sb that...表示“某人想起……”。it在句中作形式主语，真正的主语是that引导的从句。